This publication focuses on the design, implementation, testing and
operation of CPM systems that
use an algorithmic approach to detect hydraulic anomalies in pipeline
operating parameters. The
primary purpose of these systems is to provide tools that assist
pipeline controllers in detecting
commodity releases that are within the sensitivity of the algorithm.
It is intended that the CPM
system would provide an alarm and display other related data to the
pipeline controllers to aid in
decision-making. The pipeline controllers would undertake an immediate
investigation, confirm the
reason for the alarm and initiate an operational response to the
hydraulic anomaly when it
represents an operational upset or commodity release

The purpose of this publication is to assist the pipeline operator in
identifying issues relevant
to the selection, implementation, testing, and operation of a CPM
system. This document be used in
conjunction with other API publications and applicable regulations.

CONTENTS

This publication includes definitions, source and reference documents,
concepts of data
acquisition, discussion of design and operation of a pipeline as
related to CPM, field
instrumentation for CPM purposes, alarm credibility, pipeline
controller response, incident
analysis, record retention, maintenance, system testing, training,
considerations for setting alarm
limits, trending and recommendations for data presentation. The
relationship between the pipeline
controller and the CPM system is also discussed.

SCOPE LIMITATIONS

This publication is limited in scope to single-phase, liquid
pipelines. It is recognized that no
one particular methodology or technology may be applicable to all
pipelines because each pipeline
system is unique in design and operation. In addition, detectable
limits are difficult to quantify
because of the unique characteristics presented by each pipeline.
Limits must be determined and
validated on a system-by-system and perhaps a segment-by-segment
basis. Figure B-1 (along with the
discussion in Appendix B) provides a starting point for understanding
where the practical detection
limit of commodity releases starts. This publication is not all
inclusive. The reader must have an
intimate knowledge of the pipeline and may have to refer to other
publications for background or
additional information.

CPM is intended usually as a tool to be used by the pipeline
controller in the safe operation of
the pipeline. Effective operation of a pipeline requires that the
pipeline controller be familiar
with the pipeline and the tools at their disposal. CPM is not
currently intended to replace human
judgement and intervention in the shutdown of the affected pipeline
segment(s) and the closure of
remote control valves or directing field staff to close hand operated
valves on the pipeline.

This publication complements but does not replace other procedures for
monitoring the integrity of
the line. CPM systems, as well as other commodity release detection
techniques, have a detection
threshold below which commodity release detection cannot be expected.
Application of the
information in this publication will not reduce the threshold at which
a commodity release can be
detected. For example, trained pipeline controllers analyzing
SCADA-presented operating data can be
effective at detecting certain sizes (i.e., larger) commodity
releases. Third-party reports,
pipeline patrols, and employee on-site examinations can also be
effective procedures when used to
verify the integrity of the pipeline within their applicability range.

Note: This publication is in keeping with standard industry practice
and commonly used technology;
however, it is not intended to exclude other effective commodity
release detection methods.

TRANSPORTATION SYSTEMS

This publication is written for liquid onshore or offshore trunkline
systems but much of this
content may be applicable to other piping systems such as selected
gathering systems, production
flow lines, marine vessel loading/unloading, and tank terminaling
operations. CPM has typically
been applied to steel pipeline systems but may be applied to pipelines
constructed of other
materials such as PVC, polyethylene, fiberglass, and concrete. The
successful application of CPM
may be limited by the characteristics of these other materials.

Pipeline systems vary widely in their physical characteristics
including: diameter, length, pipe
wall thickness, internal roughness coefficient, pipe composition,
complexity of pipe networking,
pipeline topology, pump station configuration, and instrumentation
(quality, accuracy, placement).
These same pipeline systems can also be categorized by operational
factors such as: flow rate,
magnitude and frequency of rate/pressure fluctuations, blending,
batching, batch stripping
schemes, product type, viscosity, density, sonic velocity, bulk
modulus, vapor pressure, pressure,
temperature, and heat transfer. The CPM methodology selected must be
evaluated against what
characteristics of the pipeline are known and what is required by the
methodology to provide
acceptable results. Most CPM technologies have not thus far proven
themselves capable of providing
satisfactory CPM operation during periodic or permanent slack line
conditions. If this condition
exists in a particular pipeline, then the CPM selection criteria for
that pipeline will need to
consider that operating condition.